Contacting solid particles and gaseous fluids



July 13, 1948. c. E. HEMMINGER 2,444,990

CONTACTING SOLID PARTICLES AND GASEOUS mums Filed Sept. 12, 1941 3Sheets-Sheet 1 REACTION YA? R REGENERATION eye; o/ws' .SEPARATOR Y: LONE CONVERSION inc/v2:

FIG-l M GWSM uff July 13, 1948- c. E. HEMMINGER CONTACTING SOLIDPARTICLES AND GASEOUS FLUIDS Filed Sept. 12, 1941 3 Sheets-Sheet 2 July13, 1948. I c HEMMINGER 2,444,990

CONTACTING SOLID PARTICLES AND GASEOUS FLUIDS Filed Sept. 12, 1941 3Sheets-Sheet 3 Ems OUTLET I I l I powo p; 154 INLETE '15s I 52 POWDEROUTkET GAS \NLE-T Flew-5 harles E. Hemrm'nzqer Era/ember Clttorneqcontacting means whereby Patented July 13, 1948 CONTACTING SOLIDPARTICLES AND GASEOUS mums Charles E. He1nmin ge'r,- Westileld, N. 1.,assignor I to Standard Oil Development Company, a corporation ofDelaware Application September 12, 1941, Serial No. 410,525 8 Claims.(01. 196-52) This invention relates to treating vapors or gases withfinely divided solid contacting material and more particularly relatesto the catalytic conversion of hydrocarbons in which finely ably thevapors or gases are passed upwardly through the reaction zone and thefinely divided solid contacting material is passed downwardly throughthe reaction zone. The velocity of the vapor or gas is so adjusted thatthe solid particles are fluidizedand simulate a liquid.

According to the preferred form oi my inven-,

the reaction zone or vessel is provided with intimate contact betweenthe solid particles and the vapors or gases is obtained.

In the drawings; 1

Figure 1 represents a diagrammatic showing of apparatus adapted to carryout my invention;

Figure 2 represents an enlarged detailshowin the internal constructionof one form of contacting means in a vessel;

Figure 3 represents a horizontal cross-section taken substantially online III-III of Figure 2;

Figure 4 represents another form of reaction vessel; and

Fig. 5 represents a modification of the form of vessel shown in Fig. 4.gl

Referring now to the drawing, the reference character l0 designates areaction zone or vessel wherein vapors and gases are contacted withfinely divided solid material. The vapors or gases are introduced intothe lower portion of the vessel through line i2. Finely divided solidcont-acting material is introduced into the upper portion of the vessell8 through line l4. The contacting material may be fresh or may beregenerated. The flow of the finely divided material and vapors or gasesis counter-current in the vessel Ill and in order to eflect intimatecontact between the solids and the vapors or gases contacting means arearranged within the vessel l8.

As, shown in the drawings, the reaction zone or vessel l8 comprises abubble tray column. Instead of this construction the vessel l0 may be apacked tower or may be a disc and doughnut tower, etc. The vessel is soconstructed to provide contact between the vapors and solid particlespassing through thevessel Ill. Attention tion,

- is directed to Figure 2 which shows an enlarged r The plate ing thedetail of the vessel It and includes a plate l8 having a down spout l8for conducting solid particles from the plate I8 to the plate beneaththe plate It. Extending upwardly from the plate l8 are small tubes 22provided with caps 24 to provide passageways for the vapor or gaspassing upwardly through the vessel It. As before stated, the velocityof the vapors or gases is so adjusted that the solid particles aremaintained in a fluidized condition. The solid particles in fluidizedcondition are shown at 28 on plate It.

Arranged above the plate i8 is another plate 28 which is spaced from thewalls oi the vessel l8 as at 32 to provide passageways 88 for conuctfluidized solid particles from the plate 28 to the plate l8 directlybeneath the plate 28.

28 is also provided with upwardly extending tubes 34 provided with caps88 to provide passageways for the vapors or gases passing upwardlythrough the vessel i8 while at the same time preventing downward flow oithe fluidized solid particles through the tubes '84. The solid particlesin fluidized condition are shown at 88 on the plate 28. The fluidizedsolid particles are conducted to the plate 28 by means of a down spout42 which conducts the fluidized solid particles from a plate directlyabove the plate 28.

Beneath the first mentioned plate I6 is another plate 48 which issimilar in construction to the plate 28. Plate 48 is so arranged to havepassageways 41 for conducting the fluidized solid particles from theplate 46 to the plate 48 which is arranged beneath the plate 48. Plate48 is similar in construction to the first mentioned plate It and has adown spout 49 for conducting fluidized solid particles from the plate 48to the plate directly beneath. Preferably the down spouts 42, I8 and 49extend below the surface of the fluidized mass of the solid particles onthe respective plates.

From the above it will be seen that the vapors or gases pass upwardlythrough the vessel l8 and the velocity of the vapors or gases is soadjusted that the solid particles are fluidized and flow like a liquid.The fluidized solid particles flow downwardly in the vessel ill incountercurrent relation to the vapors or gases. For example, theupflowing vapors or gases pass through the bed '26 on plate l8 tomaintain the solid particles in fluidized condition. The fluidized solidparticles flow from the plate It through the down spout it to the nextlower plate 46. The vapors or gases pass upwardly through the bed offluidized solid particles 26 and through tubes 84 arranged on plate 28and then through the bed of solid particles 38 on the plate 28.

With the arrangement of contacting means above described, intimatecontact between the vapors or gases and solid particles is effected anda greater degree of agitation is obtained thanthe catalyst particlesbefore reusing them in an- I other conversion operation. In someinstances the catalytic particles may be recycled to the conversion zoneor vessel I8 without regeneration. The regeneration of the catalystparticles or solid particles will be hereinafter described in greaterdetail.

4 withdrawn from the bottom of the separating means 88 and passedthrough line 82 into the top portion of a regeneration zone 88. Thecontaminated solid particles from the separator 88 which are passedthrough line 84 are preferably mixed with the solid particles withdrawnfrom the bottom of the reaction zone ,0 vessel I8 and this mixture isintroduced into 16 separating means 88 just described. Line 82 ay passdirectly into the' top of vessel 88, eliminating the recovery means 88.The air in line 82 is separated from entrained solids in separatingmeans presently to be described.

Air or other suitable regenerating gas is introduced into the lowerportion of the regeneration zone 83 through line 84; The regenerationzone 83 is of substantially the same construction as the reaction zoneor-vessel I8 above described. The

The reaction products in vapor form pass overhead through line 84. Whilethe velocity of the vapors or gases through the vessel I8 is relativelylow, the reaction products carry some of the solid particlesoverhead. Itis desirable to remove these solid particles from the reaction productsand the vapors passing through line 54 areintroduced into a separatingmeans 56 which may be any suitable separating means but which is shownin the drawing as a cyclone separator. More than one separating meansmay be used if desired. In the separating means 58, vapors and gases areseparated from substantially dry solid particles. The reaction productsin vapor form pass overhead through line 58 and are further treated asdesired to separate desired constituents.

In the catalytic conversion of hydrocarbons the reaction products invapor form are preferably passed to a fractionating system where thedesired motor fuels are separated from the rest of the reactionproducts.

The separated solid particles collecting in the separator 58 arewithdrawn through line 82 and passed through line 64 having a valve 88to a regeneration zone presently to be described. In some instances itmay be desirable to rebycle some of the separated solid particles to thereaction zone or vessel I8 by means of line I4.

The contaminated solid particleswhich move downward in the reaction zoneor vessel I8 are preferably passed through a stripping section forremoving residual reaction products. In the catalytic conversion ofhydrocarbons residual hydrocarbons are removed from the catalystparticles in this section. If desired, heating coils 88 may beintroduced between the plates in the lower section of the reaction zoneor vessel I8. Steam or other suitable stripping gas is introduced intothe bottom portion of the reaction vessel or zone I8 through line 12.

The stripped solid particles are withdrawn from the bottom of thereaction zone or vessel I8 through line I4 having a valve 18. Air orother suitable regenerating gas is introduced into line I4 below line 18by means of line 18 and the contaminated solid particles are carried insuspension through line 82 to a separating means 88 for separating thesolid particles from gases. The separating means 88 is any suitableseparator and is shown on the drawing as a cyclone separator. More thanone cyclone separator may be used if desired. The separated gases passoverhead through line 88. The separated solid particles are regenerationzone 83 is provided with bubble caps and down spouts for providingintimate contact between the solid particles and the regenerating gas.The contaminated solid particles pass downwardly through theregeneration zone and the regenerating gas passes upward incountercurrent relation thereto.

The regeneration gases leave the top of the regeneration zone throughline 88 and as they carry a certain amount of solid particles with them,it is desirable to pass the regeneration gases through a separatingmeans 88 to recover the solid particles. The separating means 88 may beany suitable construction and is'shown in the drawing as a cycloneseparator. More than one separating means may be used if desired. Theregeneration gases pass overhead through'line I82 and are removed fromthe system. The separated solid particles are withdrawn from the bottomof the separating means 88 and returned to the upper portion of theregeneration zone through line I84. If line 82 passes directly into thetop of vessel 83 as above described, the air is separsated fromentrained solids in separatingmeans The solid particles duringregeneration in the regeneration zone 83 are maintained in a fluidizedcondition during their passage through the regeneration zone. Preferablythe return pipes 82 and I84 extend below the level of the fluidizedsolid particles on the top plate in the regeneration zone 83.

In the catalytic conversion of hydrocarbons carbonaceous or organicmaterial is deposited on the catalyst particles. These catalystparticles are regenerated by burning of! the carbonaceous or organicdeposits. The first part of the regeneration is most active and as thereaction is exothermic, it is desirable to prevent the temperature fromrising too high during this portion of the regeneration. Most catalyticsubstances are injured by high temperatures and therefore it isnecessary. to control the temperature during regeneration. One way ofcontrolling the temperature is to introduce cooling coils I88 betweenthe upper plates in the regeneration zone 83. -Any suitable heatexchange medium may be circulated through tubes I86.

Steam or other suitable stripping or purging gas is introduced into thebottom portion or purging zone I81 of the regeneration zone 83 throughline I88 to remove residual oxygen or regenerating gas from the solidparticles in the lower portion of the regeneration zone 88. Theregenerated solid particles are withdrawn-from the bottom of theregeneration zone 83 through line II2 having a valve H4. The regeneratedsolid particles are passed through line ,6 and introduced into the upperportion of the conversion zone or vessel I0 through line I4.

Some of the solid particles are lost from the;

.vap'or inlet I32 at the. bottom and a vapor or gas outlet I34'at thetop. The vesseljis also provided with an inlet pipe I36 extending intothe top through line I34.

portion of the vessel for introducing powdered contacting or catalyticmaterial. tom the vessel I30 is provided with a draw-off or outlet I38for' withdrawing powdered material which has passed downward through thevessel I30.

'velocity of the vapor ,or gas passing upwardly through the vessel I30aerates or fluidizes the layers of catalyst or solid particles on theperforated plates so that the catalyst orsolid particles or fluidizedmass flows like a liquid.

As powdered catalyst or solid material is continuously introduced ontothe top plate I52 by means of the inlet pipe I36, the level of thefluidized mixture rises and overflows a downflow pipe I64 which extendsthrough the top perforated plate I52. The downflow pipe is arranged sothat a portion I66 extends above the perforated plate I52 and anotherlonger portion I68 extends below the perforated plate I52 to a levelabove the next lower perforated plate I48.

The fluidized solid particles flow dbwn the pipe I64 onto the next lowerperforated plate I48 until the mass reaches the level of the pipe "2which carries the fluidized mixture to the next lower perforated plateI46. The downflow pipe "2 extends through the perforated plate I48 andhas a portion projecting above the plate I48 and another portionprojecting below the plate I48 described in connection with the firstdownflow pipe I64.

Another downflow pipe I" is provided which extends through plate I46 andwhich permits downflow of the fluidized solid particles to the nextlower perforated plate I44. Another downflow pipe "6 is provided whichextends through the perforated plate I44 and conducts the fluidizedsolid particles to the bottomperforated plate or distribution plate I42.The outlet pipe I38 extends above the perforated plate I42 so that alayer of fluidized solid particles is built up on the plate and when itreaches the top of the outlet pipe I38, it flows out of the vessel I30.

In the treatment of gases or vapors the gases or yapors are introducedinto the bottom of the vessel I30 and contact the solid particles on theseparate perforated plates as the vapor or gas travels upward. Thevelocity of the vapor or gas Near the bot-,

The vessel I30 is provided with a bottom disis so controlled that thesolid particles on the condition.- The treated gas leaves the vessel I30In passing upward the vapor or gas passes countercurrent to the movementof the solid or catalyst particles.

The solid particles are maintained on the perforated plates and as thepowdered material is introduced into the top of the vessel onto topplate I62, the fluidized mixture rises above the top I66 of the firstdownflow pipe I68 onto the next lower perforated plate I48 from which itpasses through the succeeding downflow pipes and it is withdrawn fromthe vessel I30 through outlet I38.

The apparatus shown in Figure 4 may be used as either or both reactionvessels shown in Figurc 1 of the drawing. While the apparatus may beused for the catalytic cracking of hydrocarbons, it is especiallyadapted for the regeneration of catalyst particles which have becomecoated with carbonaceous material. It will be seen that the catalystparticles containing the-most carbonaceous material are introduced intothe top of the vessel I30 where the upflowinggas has rial in the firstpart of the regeneration and by limiting the amount of oxygen, theregeneration is controlled to prevent excessively high temperatures.

When the catalyst particles arrive near the bottom of the vessel I30,most of the carbonaceous material hasbeen burnt off and it is dilflcultto remove the remaining traces of carbonaceous material. The catalystparticles in the lower portion of the vessel I30 are contacted with gascontaining a high oxygen concentration and the removal of the remainingcarbonaceous material is facilitated. I

In Figure 4 the bottom of each downflow pipe is about on a level withthe top of the next lower downflow pipe. For example, the bottom ofinlet the level of the layer would extend above the outlet end of inletpipe I36. The remaining downflow pipes may be similarly arranged toincrease the depth of the layer of fiuidized'particles on each plate.

The above modification of Fig. 4 is shown in Fig. 5 wherein the sameparts are designated by the same reference characters used in Fig. 4. InFig. 5 the downflow pipe I64 has its upper end I at a higher level thanthe bottom I82 of inlet pipe I36. Similarly the next lower downflow pipeI12 has its upper end I84 above the bottom I86 of downflow pipe I64. ,7The next lower downflow pipe "4 has its upper end I88 above the bottomI90 of downflow pipe H2. The next lower downflow pipe I'I6 has its upperend I32 above the bottom I94 of downflow pipe "4. Outlet pipe I38 hasits upper end I96 above the bottom I88 of downflow pipe I16.

With the apparatus shown in Fig. 5, the level of the fluidized solidparticles on each plate is raised by using longer 7 pipes and having thetops thereof extending above the bottoms of the draw-oi! pipes as aboveset forth in the descrip-.

tion of the modification of Fig. 4. y

In the catalytic cracking of hydrocarbons, gas oilvapors at atemperature of about 850 1!. to 1000 F. are ntroduced into the reactionvessel or zone I rough line I2. The catalyst particles at about the sametemperature or as highas 1200 F. are introduced into the upper portionof the reaction zone I0 through line I4. The catalyst is in finelydivided form and is of such a size that substantally all of the catalystparticles will pass through 50 to 400 mesh or finer oi the standardseries. As a catalyst, any suitable catalytic material may be used suchas acid activated bentonite clays, synthetic gels containing silica andalumina or silica and magnesia, etc.

During passage through the reaction zone or vessel I0, the oil vaporsare intimately contacted with the catalyst particles and are convertedto lower boiling hydrocarbons. The products of conversion pass overheadand are preferably passed through line 50 to a fractionating system forseparating desired motor fuel from higher boiling constituents.

During 'the conversion, the catalyst particles become coated withcarbonaceous material and as the catalyst particles pass into thestripping section of the've'ssel I0, residual volatile hydrocarbons areremoved. The catalyst particles with the remaining carbonaceous depositsare introduced into the top portion of the regeneration zone. ture ofabout 800 F. to 1000 F. In the regeneration zone the contaminatedcatalyst particles bonaceous material is burned from the catalystparticles. During regeneration of acid treated bentonite clays, thetemperature is maintained below about 1200 F. to prevent injuring of thecatalyst particles or, sintering thereof. The regenerated catalystparticles pass through the stripping zone or purging zone I01 in theregeneration zone 93 and are then withdrawn from the bottom. portion ofthe regeneration zone through line H2. The regenerated catalystparticles at a temperature of about 850 F. to 1200 F. are returnedthrough lines H6 and I4 to the upper portion of the reaction zone orvessel I0 for another conversion operation.

One of the important features of the invention is the counterfiowfiheatexchange of gases and solids which ay be employedior heating or coolingeither. I or instance, in the regeneration in vessel 93 hot 'products ofcombustion at about 1100 F. and deficient in oxygen heat catalyst atabout 900 F. and distill ofi residual hydrocarbons, decreasing the airrequirements for regeneration. Then, in the top section the high carboncatalyst is burnt in the presence of low oxygen concentration air. Inthe bottom section the catalyst lean in' carbon is burnt in the presenceof gas high in oxygen concentration, almost pure The catalyst particlesare at a tempera-' are intimately contacted with air and the cara bothpositive and negative so that the mass accan be utilized in manyreactions where gases react with or treat solids such as chlorination ofsolids, drying of solids, roasting o! ores, partial oxidation orcarbonization oi coal, absorption of gases by solids, gas purification,production of iron carbonyl from iron oxide and carbon monoxide and thelike.

The catalyst particles while passing through the reaction zone I0 andthe regeneration zone 93 are maintained in a fluidized condition so thatthey fiow like a liquid. In order to maintain the catalyst particles influidized condition, the velocity of the vapors passing upward inreaction zone, I0 and the velocity of the gas or gases passing upwardlyin regeneration zone 03 are about 0.5 to 3 feet per second. By havingthe contacting means, within the vessels I0 and 03, better heat controlof the interior of the reacting mass is pomible. By adding or removingheat in the heat transfer tubes, any temperature gradients in the towermay be maintained. My process is also an improvement of other vesselswhich do not contain any contacting means in that channelling is avoidedand better agitation and contact are obtained between the solidparticles and the gases or vapors.

While two forms of vessel have been shown for the reaction andregeneration zones, it is to be understood that other forms of apparatussuch as packed towers, disc and doughnut towers may be used to provideintimate contact'between the solid particles, gases orvapors, etc. whilemaintaining the solid particles infiuidized condition so that they flowdown through the tower or vessel as a-fiuidized mass. My invention isnot to be restricted to the catalytic cracking of hydrocarbons and maybe used for other catalytic reactions as for example the synthesis ofhydrocarbons from carbon monoxide and hydrogen, hydrogenation,dehydrogenation, alkylation, isomerization, polymerization, etc.

The invention lends itself to flexibility in adding or removing'gases orcatalyst from any portion of the reaction vessel. For instance, catalystmay be added or removed from different plates, and, likewise, gases maybe added or removed from each plate, the latter requiring catalystseparating means to return the catalyst to the vessel. line 202 is shownhaving valved branch lines 200,

. 200 and 208 for adding catalyst or solid partichanges may be madewithout departing from the spirit of the invention.

I claim:

1. A method of cracking hydrocarbons in the presence of powderedcracking catalyst which comprises introducing hydrocarbon vapors atcracking temperature into the bottom portion of a cracking zone andintroducing powdered catalyst particles into the upper portion of saidcracking zone wherein the fiow of hydrocarbon vapors and catalystparticles is generally countercurrent, controlling the velocity of thevapors so that the catalyst particles are in a dry fluidized conditionIn the modification shown in Fig. 5,

in said zone, removing solid dry particles from the bottom of saidcracking zone and cracked vapors from the top of said cracking zone, thefluidized particles being maintained in a plurality of spaced bedsarranged one above the other with a connecting confined verticalpassageway between the beds so that the vapors flow upwardly through thebeds to fluidize the solid catalyst particles therein and fluidizedcatalyst particles flow from a predetermined level of an upper bed to alower bed through the vertical passageway and spent catalyst particlesadjacent to the bottom portion of said cracking zone below the inlet forhydrocarbon vapors areheated by indirect heat exchange and stripped witha stripping gas.

2. The process of treating finely divided solids with gases, whichcomprises maintaining in a confined zone upflowing gas and a pluralityof permeably supported superposed beds of everchangingsolids, supplyinggas to said confined zone while controlling the velocity of theupflowing gas so that the solids of the beds are suspended in gas andmaintained in fluidized flowable condition, supplying feed solids intoupper of the superposed beds, removing fluidized solids from the top ofeach bed by overflowing them over an elevation which controls the fluidlevel of the bed, conducting into a lower bed descending solidsoverflowed from an upper-of the superposed beds, removing from saidconfined zone solids overflowed from the lower bed and removing gas froman upper section of said confined zone.

3. The process according to claim 2 wherein solids conducted into eachbed are received therein at an elevation below that from which solidsare overflowed from such bed.

4. The process according to claim 2 wherein the velocity of theupfiowing gas lies in a range from 0.5 to 3.0 feet per second.

5.- The process of treating finely divided solids with gases, whichcomprises maintaining an upflowing body of gas in a confinedzone'maintaining a plurality of superposed perviously supported beds ofever-changing solids extending horizontally across said confined spaceand spaced apart, passing gas upflowingly through the beds at a velocityfor maintaining the solids of the beds in gas-suspension and fluidizedcondition to present a fluid level, supplying gas to a bottom section ofsaid confined zone, removing gas from an upper section of said confinedzone, supplying, feed solids to the uppermost of the superposed beds,controlling the height of the fluid level of each bed, conducting solidsfrom the controlled fluid level of the lowermost bed through the bed tooutside of the gas body, dropping solids through a confined passagewayextending from the controlled fluid level of an upper bed through thatbed and through the space therebelow and releasing such dropping solidsinto the next lower bed at an elevation below its controlled fluidlevel.

6. A method of converting hydrocarbons to motor fuel in the presence ofconversion catalyst particles which comprises maintaining a plurality ofspaced beds one above the other of fluidized conversion catalystparticles in liquid-simulating condition in a conversion zone by passinghydrocarbon vapors upwardly therethrough, said conversionzone beingmaintained under desired conversion conditions, introducing catalystparticles into an upper bed of fluidized particles in said conversionzone, controlling the velocity of the hydrocarbon vapors so'that thecatalyst par- 'bed to the next lower bed through a vertical.

ticles in the beds are maintained in a liquidsimulating condition,removing catalyst particles from a lower bed of fluidized particles insaid conversion zone and converted hydrocarbons from the top of saidconversion zone, maintaining the depth of fluidized liquid-simulatingparticles in each bed substantially constant by removing catalystparticles from the upper surface of each catalyst particles and removingregenerated I catalyst particles from the bottom portion of saidregeneration zone, said regeneration zone being provided with spacerperforated plates and down spouts between said plates wherebyregenerating gas flows upwardly through the perforations in saidperforated plates and through the catalyst particles thereon to fluidizethe catalyst particles and intimate contact between the regenerating gasand catalyst particles is provided, the fluidized catalyst particlesflowing down from plate to plate through said down spouts and removingheat from the regenerating gas between certain of said plates.

8. A method of contacting gaseous fluid and solid particles whichcomprises maintaining a plurality of spaced beds one above the. other offluidized solid particles in liquid simulating condition in a contactingzone by passing gaseous fluid upwardly therethrough, introducing gaseousfluid into the lower portion of said contacting zone, introducing solidparticles into the uppermost bed of fluidized particles in saidcontacting zone, controlling the velocity of the gaseous fluid so thatthe solid particles in the beds are maintained in a liquid simulatingcondition, re-

moving solid particles from a lower portion of said contacting zone andgaseous fluid from the top of said contacting zone, controlling thedepth of the bed of particles by flowing the fluidized solid particlesfrom the top of the uppermost confined passage extending from the topsurface of the uppermost bed to the next lower bed and through the spacetherebetween so that in passing from one bed to the next the particlesin the confined passage are out of contact with the upflowing gaseousfluid, and removing at least some of the solid particles in fluidizedcondition from a bed above the bottom bed of -fluidized solid particles.

CHARLES E. HEMMINGER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Number Number Thomas Oct. 27, 1942 NameDate Deznen i Dec. 12, 1942 Keranen Aug. 3, 1943 Holt et a1 Feb. 8, 1944Melaven May 2, 1944 Conn May 23, 1944 FOREIGN PATENTS Country Date 7Great Britain Jan. 3, 1939 Fra'nce Nov. 13, 1931

